#!/usr/bin/env node
/**
 * patch-r2-tierize-input-cap.js · 2026-04-26 · P3
 * 为 pre-compact-handoff.js 的 tierize() 输入加 5 MB 上限,
 * 防极端 transcript (单条 tool_result > 5 MB) 拖慢 PreCompact hook
 *
 * Idempotent: sentinel 'R2-INPUT-CAP-V2'
 * 风险: 极低 — 仅对 size > 5MB 的单条记录截断, 不影响小输出
 */
'use strict';
const fs = require('fs');
const path = require('path');

const HOOK = path.join(process.env.HOME || process.env.USERPROFILE || 'C:/Users/leesu', '.claude', 'hooks', 'pre-compact-handoff.js');
const SENTINEL = 'R2-INPUT-CAP-V2';

// 自适应行尾 (源文件可能 CRLF)
function detectEol(s) { return s.includes('\r\n') ? '\r\n' : '\n'; }
function withEol(s, eol) { return s.replace(/\r?\n/g, eol); }

const OLD_LF = "        const size = Buffer.byteLength(text, 'utf8');\n        if (size < 500) continue;\n        items.push({ size, text, tool_use_id: part.tool_use_id });";

const NEW_LF = "        const size = Buffer.byteLength(text, 'utf8');\n        if (size < 500) continue;\n        // R2-INPUT-CAP-V2: 单条 tool_result > 5MB 截断, 防 tierize 正则扫描超时\n        const MAX_ITEM_BYTES = 5 * 1024 * 1024;\n        const safeText = size > MAX_ITEM_BYTES ? text.slice(0, MAX_ITEM_BYTES) : text;\n        items.push({ size, text: safeText, tool_use_id: part.tool_use_id, capped: size > MAX_ITEM_BYTES });";

try {
  let raw = fs.readFileSync(HOOK, 'utf8');
  if (raw.includes(SENTINEL)) {
    console.log('[r2-cap] already applied, skip');
    process.exit(0);
  }
  const eol = detectEol(raw);
  const OLD = withEol(OLD_LF, eol);
  const NEW = withEol(NEW_LF, eol);
  if (!raw.includes(OLD)) {
    console.error('[r2-cap] anchor not found, abort');
    process.exit(1);
  }
  fs.writeFileSync(HOOK + '.bak.r2cap.' + Date.now(), raw, 'utf8');
  raw = raw.replace(OLD, NEW);
  fs.writeFileSync(HOOK, raw, 'utf8');
  console.log('[r2-cap] applied');
} catch (e) {
  console.error('[r2-cap] error:', e.message);
  process.exit(1);
}